1. Technical Field
The present invention relates to an illumination apparatus, and more particularly, to an illumination apparatus having a light guide member of a long article.
2. Related Art
Patent Document 1 discloses an illumination apparatus for a vehicle cabin where an illumination member of a long article having a light guide property is disposed on an instrument panel, an upper part of the instrument panel is formed with a recess portion, the recess portion opens downwardly, the illumination member is accommodated in the recess portion, a cover member is attached and fixed to the opening of the recess portion and light emitted from the illumination member is illuminated from the opening of the recess portion to an outside through the cover member.
Patent Document 2 discloses an illumination apparatus for a vehicle having a long light guide member and a light source configured to make light incident on an end surface of the light guide member in a longitudinal direction, where the light guide member is accommodated in a housing, the housing is attached to a molding and the light emitted from the light guide member is illuminated from an opening configured by the housing and the molding to an outside.
[Patent Document 1] Japanese Patent No. 4,737,241B
[Patent Document 2] Japanese Patent No. 5,225,744B
In the technology of Patent Document 1, a distance (a distance between the illumination member and the cover member) between the illumination member and the opening of the recess portion is constant in a longitudinal direction of the illumination member.
Therefore, a shape of an illumination range (an illumination region) of the light emitted from the illumination member is similar to a shape (a long rectangular shape) of the opening of the recess portion and an illuminance in the illumination range is uniform, so that an illuminance difference (a contrast) between an internal and an external of the illumination range is increased.
For this reason, when an illumination target is very close to the illumination member, particularly, a boundary of the illumination range is clearly illuminated to the illumination target, so that an illumination effect of a soft texture by indirect illumination is deteriorated.
In the technology of Patent Document 2, a distance between the light guide member and the opening is constant in the longitudinal direction of the light guide member.
Therefore, a shape of an illumination range of the light emitted from the light guide member is similar to a shape (a long rectangular shape) of the opening and an illuminance in the illumination range is uniform, so that an illuminance difference between an internal and an external of the illumination range is increased.
For this reason, when an illumination target is very close to the light guide member, particularly, a boundary of the illumination range is clearly illuminated to the illumination target, so that an illumination effect of a soft texture by indirect illumination is deteriorated.
In recent years, for the indirect illumination of which illumination range has a long linear shape, it is required to improve the illumination effect of the indirect illumination by gradually decreasing the illuminance towards an end portion of the illumination range in a longitudinal direction and gradually narrowing a width of the illumination range in a width direction.
It is therefore an object of the present invention to provide an illumination apparatus capable of improving an illumination effect of indirect illumination.